The present invention relates to parallel-connected gate turn-off thyristors (GTOs), and in particular to a parallel-connected GTO which is suitable for almost matching the turn-on and turn-off operations of each element of GTOs connected in parallel.
In general, each of GTOs connected in parallel has slightly different characteristics. Therefore, even when equal gate currents are applied to them, they sometimes do not start to operate simultaneously. In other words, when they are turned on, some of them turn on quickly and the remaining elements are delayed. When being turned off, some of them turn off quickly and again the remaining elements are delayed. In this case, an overcurrent flows temporarily into a GTO which has turned on or turned off quickly, and this means that such a GTO deteriorates and can even break down.